The invention relates to a semiconductor device comprising a semiconductor body with an integrated circuit having a vertical transistor comprising a collector zone of a first conductivity type, a base region of a second conductivity type disposed on at least a part of the collector region and an emitter region comprising at least one zone of the first conductivity type included in a part of the base region adjoining a major surface of the semiconductor body.
In known bipolar transistors, the inverse current amplification .beta..sub.I defined as the ratio between the emitter current I.sub.E and the base current I.sub.B when the collector-base junction is polarized in the inverse sense is usually not very high.
However in certain applications, it is desirable to have available transistors having a high inverse current amplification .beta..sub.I of, for example several tens. In that case, it is possible to improve the collector-base voltage V.sub.CEsat of the transistor in saturation or, whilst utilizing the transistor in the inverse sense, to realize a multi-collector transistor.